Generally, the module comprises an electrically non-conductive substrate which bears the microcircuit on one of its faces and, in the case of contact type cards, an external contact interface on the opposite face, this interface being electrically connected to the microcircuit, through the substrate for example.
Dual cards generally comprise a body which incorporates the antenna as well as the electronic module, housed in a cavity provided in the body.
The antenna and the microcircuit are then conventionally connected electrically by means of metal studs during the interleaving of the module into the body.
Such a structural arrangement makes it possible to obtain relatively good communication range because the dimensions of the antenna are maximized within the limit of the dimensions of the card body. However, the connection of the microcircuit to the antenna has a certain number of disadvantages, particularly in terms of reliability and of production efficiency.
In order to correct these disadvantages, it is thus known to integrate the antenna directly into the electronic module, for example on the substrate bearing the microcircuit, and then to transfer the module into the body of the card using traditional interleaving techniques for conventional contact type cards.
Ordinarily, the dimensions of the substrate are limited to the dimensions of the interface of external contacts having a generally square or circular shape so that the substrate is entirely masked by the metal interface.
But the incorporation of the antenna into the module imposes a substantial increase in the dimensions of that substrate so that the antenna has an effective reception area for the magnetic field that is sufficient to maintain a satisfactory communication range.
However, in this case, a relatively large area of the substrate is not covered by the antenna and by the external contact interface, the antenna extending generally along the periphery of the substrate. This surface of substrate in the raw state produces a particularly unattractive effect in the card and gives an impression of poor quality manufacture.